Art is a recurring motif throughout the poem. The piece starts with the speaker calling the listener’s attention to one piece of art and ends with him similarly pointing out another one. The central piece of art in the poem is the titular portrait of the last duchess, the duke’s late wife. It sets the context of the poem, allowing for the circumstance of the monologue and becoming the object around which the narrative revolves and unravels.

The art in the poem serves to highlight the character of the duke. Both the duchess’s portrait and the statue of Neptune indicate the duke’s acquisitiveness and possessive nature. Hi indicates the statue, for instance, is a rarity, calling to his desire for and pleasure in collecting objects of value. Similarly, the duke mentions how only he is allowed to draw back the curtain covering the portrait, indicating a possessive streak. In addition, the duke mentions the names of the artists responsible for both pieces of work. Although fictional artists, they can be presumed to be well reputed and talented, as the duke expects the listener to know and appreciate the names he lists.